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Naming.unbind("somename") fails against wildfly 13

I'm migrating an app from jboss 4.2 to wildfly 13. The app exposes EJBs, successfully migrated and these EJBs are used by some standalone clients (wrapped as services with tanuki wrapper) running on the same machine as wildfly. These standalone clients are monitored using JMX.
The startup code tries to unbind the service name in case the client crashed in an earlier run using
Naming.unbind("//localhost:1099/myService");
On normal startup (not after a crash) a
java.rmi.NotBoundException
is expected.
My issue is I get the following stacktrace
Caused by: java.net.ConnectException: Connection refused: connect
at java.net.DualStackPlainSocketImpl.connect0(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:79)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:589)
at java.net.Socket.connect(Socket.java:538)
at java.net.Socket.<init>(Socket.java:434)
at java.net.Socket.<init>(Socket.java:211)
at sun.rmi.transport.proxy.RMIDirectSocketFactory.createSocket(RMIDirectSocketFactory.java:40)
at sun.rmi.transport.proxy.RMIMasterSocketFactory.createSocket(RMIMasterSocketFactory.java:148)
at sun.rmi.transport.tcp.TCPEndpoint.newSocket(TCPEndpoint.java:613)
port 1099 is the default "well known" port as stated by the Naming javadoc:
The Naming class provides methods for storing and obtaining references
to remote objects in a remote object registry. Each method of the
Naming class takes as one of its arguments a name that is a
java.lang.String in URL format (without the scheme component) of the
form:
//host:port/name
where host is the host (remote or local) where the registry is located, port is the port number on which the registry accepts calls,
and where name is a simple string uninterpreted by the registry. Both
host and port are optional. If host is omitted, the host defaults to
the local host. If port is omitted, then the port defaults to 1099,
the "well-known" port that RMI's registry, rmiregistry, uses.
I also tried with wildfly management port as it uses http port upgrade, I get
java.rmi.ConnectIOException: error during JRMP connection establishment; nested exception is:
java.net.SocketTimeoutException: Read timed out
with the following root cause
Caused by: java.net.SocketTimeoutException: Read timed out
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.socketRead(SocketInputStream.java:116)
at java.net.SocketInputStream.read(SocketInputStream.java:171)
at java.net.SocketInputStream.read(SocketInputStream.java:141)
at java.io.BufferedInputStream.fill(BufferedInputStream.java:246)
at java.io.BufferedInputStream.read(BufferedInputStream.java:265)
at java.io.DataInputStream.readByte(DataInputStream.java:265)
at sun.rmi.transport.tcp.TCPChannel.createConnection(TCPChannel.java:246)
What am I missing and/or doing wrong?

I found that the rmiregistry is not started by wildfly. I was mislead by our old environment that starts rmiregistry on OS startup by init.d.
So starting the rmiregistry solved my problem.
Rmi and wildfly http upgrade feature are not related to each other since rmiregistry is an independent process.

Connection refused when connecting to RabbitMQ via IP address instead of localhost

I'm trying to set up a RabbitMQ server (version 3.7.4, installed via homebrew on macOS 10.13.4) such that my colleagues can work with it via the internal network. We are using the official Java client (com.rabbitmq:amqp-client:5.2.0). Unfortunately, they only get a ConnectException with the message Connection refused:
java.net.ConnectException: Connection refused (Connection refused)
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:589)
at com.rabbitmq.client.impl.SocketFrameHandlerFactory.create(SocketFrameHandlerFactory.java:60)
at com.rabbitmq.client.impl.recovery.RecoveryAwareAMQConnectionFactory.newConnection(RecoveryAwareAMQConnectionFactory.java:62)
at com.rabbitmq.client.impl.recovery.AutorecoveringConnection.init(AutorecoveringConnection.java:134)
at com.rabbitmq.client.ConnectionFactory.newConnection(ConnectionFactory.java:997)
at com.rabbitmq.client.ConnectionFactory.newConnection(ConnectionFactory.java:956)
at com.rabbitmq.client.ConnectionFactory.newConnection(ConnectionFactory.java:914)
at com.rabbitmq.client.ConnectionFactory.newConnection(ConnectionFactory.java:1068)
at my.own.private.RabbitMqConnector.connect(RabbitMqConnector.java:29)
We already set up another user account (not guest) which has admin privileges. With almost the same Java code I can connect locally (setting the host to localhost) but not if I use my IP address. According to the RabbitMQ docs, the RabbitMQ server binds to all network interfaces by default (otherwise I would have said that it's a problem with address binding). I disabled my firewall so that shouldn't be the problem.
Here's the respective code:
final ConnectionFactory connectionFactory = new ConnectionFactory();
connectionFactory.setUsername("username");
connectionFactory.setPassword("password");
connectionFactory.setHost("10.10.33.12");
connectionFactory.setPort(5672);
connectionFactory.setVirtualHost("/");
try (final Connection connection = connectionFactory.newConnection()) {
// doo stuff with the connection
}

I finally found the actual problem and it's not related to Java or how I configured the ConnectionFactory. It was indeed a problem how the RabbitMQ package for homebrew is configured. In the rabbitmq-env.conf file, there was the following setting
NODE_IP_ADDRESS=127.0.0.1
This setting caused RabbitMQ to only listen on 127.0.0.1 for incoming connections. Once I removed the setting and restarted the service, I could connect from other machines as well.
Thank you all for your help!

The issue is not with your code. I would suggest you to check such things:
RabbitMQ Server is up and running
Your custom user can access virtual host "/"
Check firewall settings if any, probably it's refusing connection with remote host
One of these should be the cause, hope it helps!

Spring boot mongo mongoSocketException

I am using spring boot for my rest api but I have a problem about mongo database. Application sometimes throws mongo socket exception and does not execute following codes, when endpoint which needs mongo operation is triggred. I assign true to value of socketkeepalive but it did bot solve my problem. How can I get rid of this problem and can you offer me spring boot mongo db configuration values that are suitable?
By the way, program is working properly. But sometimes it throws this exception.
Thanks
INFO org.mongodb.driver.cluster - Exception in monitor thread while connecting to server **.***.***.***:42015
com.mongodb.MongoSocketOpenException: Exception opening socket
at com.mongodb.connection.SocketStream.open(SocketStream.java:63)
at com.mongodb.connection.InternalStreamConnection.open(InternalStreamConnection.java:115)
at com.mongodb.connection.DefaultServerMonitor$ServerMonitorRunnable.run(DefaultServerMonitor.java:127)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.net.ConnectException: Connection refused (Connection refused)
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:589)
at com.mongodb.connection.SocketStreamHelper.initialize(SocketStreamHelper.java:57)
at com.mongodb.connection.SocketStream.open(SocketStream.java:58)
... 3 common frames omitted

Spring Boot has a feature called "auto configuration". In this case, as soon as the Mongo driver is detected on the classpath, the MongoAutoConfiguration is activated with default values, which point to localhost:27017. If you don't want that behaviour, you can now either configure the properties for MongoDB (see http://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#boot-features-mongodb for valid property keys) or disable the MongoAutoConfiguration:
#SpringBootApplication(exclude = {MongoAutoConfiguration.class, MongoDataAutoConfiguration.class})
Spring boot throws this exception when Mongo DB is not running. Please make sure that Mongodb is running. It got resolved for me after starting Mongo DB.
you can check if mongoDB is running on 27017 is running or not. use this code in your terminal
netstat -plntu
And Please show me your configurations file or properties file.

Got the same issue while running mongo inside a docker stack and i just missed the port mapping from 27017 (external) to 27017 (internal), so applying
ports:
- 27017:27017
to my docker-compose.yml file worked for me.

java.rmi.ConnectException: Connection refused to host:

java.rmi.ConnectException: Connection refused to host: IPSERVER0.0.0.0.0; nested exception is:
java.net.ConnectException: Connection timed out
at sun.rmi.transport.tcp.TCPEndpoint.newSocket(TCPEndpoint.java:619)
at sun.rmi.transport.tcp.TCPChannel.createConnection(TCPChannel.java:216)
at sun.rmi.transport.tcp.TCPChannel.newConnection(TCPChannel.java:202)
at sun.rmi.server.UnicastRef.newCall(UnicastRef.java:340)
at sun.rmi.registry.RegistryImpl_Stub.lookup(Unknown Source)
at java.rmi.Naming.lookup(Naming.java:101)
at StartRMI.go(StartRMI.java:14)
at StartRMI.main(StartRMI.java:6)
Caused by: java.net.ConnectException: Connection timed out
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:391)
at java.net.Socket.connect(Socket.java:579)
at java.net.Socket.connect(Socket.java:528)
at java.net.Socket.<init>(Socket.java:425)
at java.net.Socket.<init>(Socket.java:208)
at sun.rmi.transport.proxy.RMIDirectSocketFactory.createSocket(RMIDirectSocketFactory.java:40)
at sun.rmi.transport.proxy.RMIMasterSocketFactory.createSocket(RMIMasterSocketFactory.java:146)
at sun.rmi.transport.tcp.TCPEndpoint.newSocket(TCPEndpoint.java:613)
... 7 more
I get this exception when I try to connect a remote client to my server. My Server is running RMI Server fine, and there no firewall installed. How to fix that issue ?

Check all you network adapters ,some time a VM network adapter interferes in this way .
Which is you current localhost or 127.0.0.1 is not any more referring to you host name or current machine ,which then create a connection refused problem. My General Recommendation is:
1.To check or disable unwanted VM or Network Adapters
2.Ping 127.0.0.1
3.Disable Firewall and Test if all the above doesn't work
4.Add security Manager with a policy file on you server if you haven't done that.

You have not mentioned which OS you are using, if everything is correct in terms of code and firewall then you may need to check the host entries or ip table rules.

Is IPSERVER mapped in /etc/hosts file to the IP address you want?
Check what you get when you do a hostname -i or hostname.
Try putting your IP address instead of the domain name.

Try to start the RMI registry using
start rmiregistry
for default port or
rmiregistry <port_no>
for a specified port.

Mysql and java connection issue on ubuntu communication link failure

Here is the scenario
I am trying to connect to mysql database server from the core java app using spring. My application and server runs on different box i.e. Have limited ports open
Here is what I have done soo far
I am able to telnet to port 5506 (on which my database server run ) from the client machine
I am able to connect to database server from command prompt(mysql client) from client machine
3.I tried all driver version from 5.0.8 to latest
and off course same code works on everywhere except production :)
Somehow I started thinking that Java process required more ports to be open
Here is the exception
org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is com.mysql.jdbc.CommunicationsException: Communications link failure due to underlying exception:
** BEGIN NESTED EXCEPTION **
java.net.ConnectException
MESSAGE: Connection refused
STACKTRACE:
java.net.ConnectException: Connection refused
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:327)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:193)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:180)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:384)
at java.net.Socket.connect(Socket.java:546)
at java.net.Socket.connect(Socket.java:495)
at java.net.Socket.<init>(Socket.java:392)
at java.net.Socket.<init>(Socket.java:235)
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:256)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:271)
at com.mysql.jdbc.Connection.createNewIO(Connection.java:2771)
at com.mysql.jdbc.Connection.<init>(Connection.java:1555)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:285)
at java.sql.DriverManager.getConnection(DriverManager.java:620)
at java.sql.DriverManager.getConnection(DriverManager.java:169)
at org.springframework.jdbc.datasource.DriverManagerDataSource.getConnectionFromDriverManager(DriverManagerDataSource.java:173)
at org.springframework.jdbc.datasource.DriverManagerDataSource.getConnectionFromDriver(DriverManagerDataSource.java:164)
at org.springframework.jdbc.datasource.AbstractDriverBasedDataSource.getConnectionFromDriver(AbstractDriverBasedDataSource.java:149)
at org.springframework.jdbc.datasource.AbstractDriverBasedDataSource.getConnection(AbstractDriverBasedDataSource.java:119)
at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:113)
at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:79)
at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:381)
at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:455)
at org.springframework.jdbc.core.JdbcTemplate.queryForRowSet(JdbcTemplate.java:498)
at

Have you specified the 5506 port in the connection URL? This port is not the default one for MySQL (3306).